<span>{ x+5y=7 \ 3 => {3x + 15y = 21 </span>=> {x=2 => { x=2 <span>
{ x-3y = -1 \ 5 + { 3* 2 + 15y = 21 { y=1
{5x - 15y = -5 6 + 15y = 21
8x= 16 15y =21 -6
x= 2 15y= 15
y= 1 Ответ: 2;1</span>
6х-2+15=9х-12-7
6х-9х=-13-12-7
-3х=-32
х=32/3=10⅔
4/ 7 меньше 4/ 5
3/ 5 больше 3/ 7